Py—GC—MS和LC—MS技术在褐煤结构研究中的应用

Ｄａｍｓｔｅ等用快速热解－气相色谱和快速热解气相色谱－质谱法对西班牙的五种褐煤进行了分子结构研究。用该项技术，使煤中大分子有机结构在惰性气氛中降解，形成的化合物在线分离，鉴定和定量分析，得到了用其它方法难以取得的较详细的煤大分子结构信息。Ｂｏｎｎｅｔｔ等借助流动带界面液相色谱－质谱法对煤中卟啉同系物进行了分离和鉴定。此法可证明Ｃ３２，Ｃ３１，Ｃ３０和Ｃ２９多烷基卟啉在劣质褐煤抽提物离析出的血红素馏     

煤—水混合物燃烧试验成功

<正> 英国的CUR研究所成功地进行了。由65％的煤,35％的水组成的料将在流动床式加压仅应器内烧燃的首次试验。煤一水渴合物以每小时93磅(42kg)的速效,经泵压入反应器,在流动床保持一定的温度,燃烧效率维持在99％的情况     

943颜料分散剂对酞菁蓝—醇酸清漆体系分散稳定性的影响

本文用流变性方法分析了酞菁蓝－醇酸清漆分散体系的分散稳定性，同时用沉降和透射电镜等直接方法对分散体系的分散稳定性进行了确证。结果表明，添加了９４３颜料分散剂的酞菁蓝－醇酸体系的分散稳定性变化，其流动行为趋近宾汉流体；而未加分散的酞菁蓝－醇酸清漆体系中，酞菁蓝粒子易沉降，返粗，其流动曲线形成明显的触变环。     

EVA—g-MAH反应挤出研究及其在LDPE／MH体系中的应用

采用同向双螺杆研究了不同融指的复合EVA熔融接枝马来酸酐，考察了引发剂用量，MAH用量对接枝率及熔体流动速率的影响。结果表明，接枝率随着马来酸酐、引发剂用量的增加而增加，熔体流动速率随着引发剂用量的增加减少。通过制备的接枝物添加到阻燃体系中，考查了接枝率对体系性能的影响。     

冶金焦气孔壁强度的评价

焦炭强度是冶金焦中最重要的指标之一，工业上大多用旋转强度试验时的焦炭粉化量即转鼓指数来评价。关于转鼓指数与原料煤加热时流动度的关系，一般认为流动度越低，受流动度的影响也就越大（流动度控制区）。当流动度超过一定值后，则受原料煤煤化度的影响较大（煤化度控制区）。     

水煤浆流动特性及其流变模型确定方法综述

水煤浆是一种以煤代油的理想燃料，本文就水煤浆流动特性及其流变模型确定方法进行了综述，提出了有关水煤浆流动特性方面的一些问题。     

基氏流动度在配煤炼焦中的应用

针对迁安中化炼焦煤采用常规煤质指标分析出现的单种煤常规指标较好,配煤炼焦后焦炭强度下降的问题,采用基氏流动度分析了常用两种中强黏结性炼焦煤A煤和B煤的煤质,探讨了其与常规煤质指标的关系,介绍了基氏流动度在配煤炼焦中的应用情况及存在问题。结果发现,A煤和B煤的常规煤质指标接近,最大基氏流动度分别为7209 ddpm和829 ddpm,可以较好区分两种煤;基氏流动度特征指标中的软化温度、塑性温度区间及最大流动度可反映炼焦煤的基本性质;炼焦煤的最大流动度的对数值在2.2~3.0、挥发分在23%~27%时,焦炭M40>87%、M10<7%。     

反相离子抑制色谱法分离苯胺—N—烷基化取代物

本文采用ＤＡＤ检测器，在ＲＰ－１８反相柱上对一系列苯胺－Ｎ－烷基化取代物进行了分离。选择含不同浓度三乙胺的ＣＨ３ＯＨ／Ｈ２Ｏ体系作流动相，采用正交实验分析法，确定最佳的测试条件。     

NMR法评价煤粘结性与焦炭性质的关系

在炼焦过程中，煤在焦炉中干馏软化熔融后再次固化，形成焦炭组织。煤的粘结性是表示软化熔融现象的指标，测定煤粘结性的方法主要有采用基氏塑性仪的流动度试验方法和采用膨胀计的膨胀度试验方法，并且成为试验标准（JIS M 8801）。此外。对流动度极低的非、弱粘结煤通常采用罗加试验法（JIS M 8801）和粘结力系数测定其粘结性。     

不同区域气煤对焦炭质量的影响研究

针对气煤配用量对焦炭质量的影响，通过来自不同产地4种气煤的各项指标进行分析检测并将气煤按一定比例进行配煤炼焦实验，考察了其变质程度、基式流动度及碱度催化指数对焦炭热态的影响。试验结果表明：气煤的变质程度及基式流动度特征指标对焦炭热态性能影响较大，碱度催化指数影响次之。为炼焦配煤选择气煤品种和制定配煤比例提供了技术依据，对实际生产应用具有一定的指导意义。     

Evolution of shell formation process in PP/PMMA/PS ternary blends: correlation between the melt rheology and phase morphology

Correlation between the melt rheology and phase morphology of PP/PMMA/PS ternary blends during the shell formation process were studied in detail. In this PP-matrix ternary system, theoretical predictions in agreement with the direct SEM observations demonstrated the core-shell morphology with PMMA and PS phases as core and shell phases, respectively. Morphological observations revealed that the complete shell formation takes place at about 12 and 9 wt% of PS minor phase in ternary blends composed of low and high viscosity PMMAs, respectively. In terms of rheological properties, this was corresponding to the maximum value on the storage modulus versus PS content (shell thickness) curves. Encapsulation of high viscosity PMMA core particles at lower PS contents was related to the bigger particles and low interfacial area in this system compared to the system with low viscosity PMMA core particles. At high PS contents, single and multi-core structures were observed for composite droplets of ternary blends containing low and high viscosity PMMAs, respectively. The single core morphology of low viscosity PMMA particles was related to the coalescence of core particles after the coalescence of the corresponding shells, while high viscosity PMMA cores are less likely to coalescence, leading to creation of multi-core morphology in latter system.     

Compatibility and thermal properties of poly(acrylonitrile–butadiene–styrene) copolymer blends with poly(methyl methacrylate) and poly(styrene‐co‐acrylonitrile)

The mechanical and heat‐resistant properties of acrylonitrile–butadiene–styrene (ABS) binary and ternary blends were investigated. The relationship of compatibility and properties was discussed. The results show that poly(methyl methacrylate) (PMMA) and styrene–maleic anhydride (SMA) can improve the thermal properties of conventional ABS. The Izod impact property of ABS/PMMA blends increases significantly with the addition of PMMA, whereas that of ABS/SMA blends decreases significantly with the addition of SMA. Blends mixed with high‐viscosity PMMA are characterized by higher heat‐distortion temperature (HDT), and their heat resistance is similar to that of blends mixed with SMA. For high‐viscosity PMMA, from 10 to 20%, it is clear that blends appear at the brittle–ductile transition, which is related to the compatibility of the two phases. TEM micrographs show low‐content and high‐viscosity PMMA in large, abnormally shaped forms in the matrix. Compatibility between PMMA and ABS is dependent on both the amount and the viscosity of PMMA. When the amount of high‐viscosity PMMA varied from 10 to 20 wt %, the morphology of the ABS binary blends varied from poor to satisfactory compatibility. As the viscosity of PMMA decreases, the critical amount of PMMA needed for the compatibility of the two phases also decreases. SMA, as a compatibilizer, improved the interfacial adhesiveness of ABS and PMMA, which results in PMMA having good dispersion in the matrix. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2652–2660, 2002     

Effects of a Hindered Amine Stabilizer (HAS) on radiolytic and thermal stability of poly(methyl methacrylate)

Commercial Poly(methyl methacrylate) (PMMA) containing Tinuvin 622, a Hindered Amine Stabilizer (HAS), in 0.3% (wt/wt) concentration was investigated. The samples were irradiated with gamma radiation (⁶⁰Co) at room temperature in air. The viscosity‐average molecular weight (M_v) was analyzed by viscosity technique. Both control PMMA (without HAS) and PMMA + 622 (with HAS) showed a decrease in molecular weight with the increase in dose, reflecting the random scissions that occurred in the main chain. The G value (scissions/100 eV of energy transferred to the system) was also obtained by viscosity analysis. G value results showed that the addition of Tinuvin 622 into the PMMA matrix significantly decreased the number of scissions/100 eV at dose range of 0–60 kGy. Analysis of infrared spectra showed a decrease in the carbonyl index (CI) in irradiated samples. However the CI decrease was found lower for PMMA + 622 than for control PMMA sample. Thermogravimetric analysis (TGA) revealed that maximum decomposition temperature of additive PMMA is 42°C higher than control PMMA for unirradiated system. On the other hand this difference is not significant in irradiated systems at 60‐kGy irradiation dose. The activation energy of the thermal degradation of PMMA was 165 kJ/mol, this activation energy increased 60 kJ/mol when Tinuvin 622 was added to PMMA matrix. Therefore Tinuvin 622 is a suitable radiostabilizing agent for commercial PMMA in a 0–60 kGy dose interval. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

ABS/PMMA合金流变行为的研究

对丙烯腈 丁二烯 苯乙烯共聚物(ABS)和聚甲基丙烯酸甲酯(PMMA)合金的流变行为进行了较详细的研究。内容包括:不同配比ABS PMMA混合物的熔体表观粘度随温度的变化;不同配比ABS PMMA混合物的熔体表观粘度随剪切速率的变化;相同配比ABS PMMA(70 30)混合物的熔体表观粘度随温度及剪切速率的变化。研究结果表明,ABS PMMA混合物熔体表观粘度随着体系中PMMA含量的增加而逐渐升高;高PMMA含量的ABS PM MA混合物的熔体表观粘度对温度更敏感。     

Supercritical carbon dioxide assisted blending of polystyrene and poly(methyl methyacrylate)

A method for blending polystyrene and poly(methyl methacrylate), (PMMA), with the addition of supercritical carbon dioxide has been investigated. The first series of blends was a PMMA and polystyrene with similar melt viscosities. The second series of blends was a PMMA and polystyrene with a viscosity ratio (ηPMMA/ηpolystyrene) of about 20. The results show that a reduction in the size of the minor or dispersed phase is achieved when supercritical carbon dioxide is added to the blend system. A high-pressure mixing vessel was used to prepare the blends under pressure with carbon dioxide for batch blending. The solubilities of CO₂ in PMMA and polystyrene, measured in the high-pressure mixing vessel at 200°C and 13.78 MPa (2000 psi) was 5.8 and 3.6 wt%, respectively. A single screw extruder was used to study the effects of carbon dioxide on the viscosity of polymer melts. The melt viscosity of PMMA was reduced by up to 70% with approximately 0.4 wt% CO₂. The melt viscosity of polystyrene was reduced by up to 56% with a CO₂ content of 0.3 wt%. A twin screw extruder was used to study the effects of injecting carbon dioxide in a continuous compounding operation.     

玻纤增强PMMA复合材料的流变行为研究

研究了长玻纤和短玻纤增强聚甲基丙烯酸甲酯(PMMA)复合材料的动态流变性能.结果表明,由于长玻纤比短玻纤更易发生缠结,长玻纤增强PMMA复合材料具有更高的动态模量和动态粘度,且其模量和粘度具有更高的浓度依赖性;长玻纤增强PMMA复合材料时,随着玻纤含量的增加,剪切变稀现象更加明显.     

Model filled polymers: The effect of particle size on the rheology of filled poly(methyl methacrylate) composites

The effect of size of crosslinked monodisperse spherical polymer particles on the steady shear and dynamic rheology of filled poly(methyl methacrylate) (PMMA) composites was studied for PMMA and polystyrene (PS) particles in the range from 0.1 to 1.3 micron particle size. For PMMA matrices filled with crosslinked PS particles, reduction in filler size increases non‐Newtonian behavior. Particle size effects on the rheology of filled PMMA were much less pronounced for PMMA filler. The rate of growth of steady shear viscosity with aging time was much larger for PMMA filled with PS particles than with PMMA particles. The apparent yield stress of filled PMMA composites was estimated from Casson plots. The yield stress was negligible for PMMA filler but increased with decreasing particle size for PS filler. We suggest that PS particles are rejected by the PMMA matrix and form clusters, causing large enhancements in viscosity and moduli. Polym. Eng. Sci. 44:452–462, 2004. © 2004 Society of Plastics Engineers.     

Miscible and immiscible blends of ABS with PMMA. II. Mechanical and surface properties

Mechanical and surface properties of injection-molded specimens for miscible and immiscible blends of ABS with PMMA were investigated. Regardless of miscibility, hardness, modulus, and strength of the blends generally showed a smooth variation with composition, with the possible exception of impact strength. In miscible blends, impact strength decreased smoothly with PMMA; however, in immiscible blends, a drastic drop to less than the half that of ABS was obtained at 10 wt % PMMA. Compounding at higher temperature gave decreased modulus and strength and increased impact strength. Surface gloss decreased with PMMA addition in the miscible system and increased in the immiscible system up to 50 wt % PMMA. From contact-angle and FTIR measurements, it is suggested that the surface properties are governed by miscibility and the viscosity ratio of the components. © 1993 John Wiley & Sons, Inc.     

A method to control the dispersion of carbon black in an immiscible polymer blend

The dispersion of carbon black (CB) in an immiscible polymer blend of poly‐(methyl methacrylate) (PMMA) and polypropylene (PP) was studied as the viscosity of PMMA increased. It was found that the dispersion of carbon black was strongly influenced by the viscosity of PMMA. The CB was dispersed in the PMMA phase when the viscosities of PMMA and PP are comparable, as predicted by Sumita's model. As the viscosity of PMMA increases, the CB was found to be located at the interface between the PMMA and PP phases. On further increase in the viscosity of PMMA, the CB was found to be dispersed in the PP phase. In addition, the CB dispersion in the PP/PMMA blends can significantly influence the positive temperature coefficient (PTC) intensity of the blends.     

纳米TiO2的表面处理对PET/TiO2复合材料流变特性的影响

采用表面接枝改性的方法对纳米TiO2进行表面修饰,通过熔融共混制得PET/TiO2纳米复合材料,研究了不同表面特性的PET/TiO2复合材料的流变特性。结果表明:加入纳米TiO2的PET体系粘度降低,经表面接枝偶联剂γ-缩水甘油醚氧丙基三甲基硅烷(GPS)或聚甲基丙烯酸甲酯(PMMA)的TiO2对PET粘度的降低程度减弱,当纳米TiO2质量分数大于3%时,粘度趋于稳定。PET/PMMA-TiO2复合体系的粘流活化能最大,温度敏感性强。